Exam 17: Object-Oriented Design

The reserved word ______ represents a reference that does not point to a valid object.

What is an aggregate object?

A reference variable can refer to any object created from any class related to it by ___________.

What are constructors used for? How are they defined?

A polymorphic reference uses the type of the reference, not the type of the object, to determine which version of a method to invoke.

Instance variables should be declared with public visibility to promote encapsulation.

How is overriding related to polymorphism?

Inheritance can be applied to interfaces, so that one interface can be derived from another interface.

Interfaces allow us to make ______ references, in which the method that is invoked is based on the particular object being referenced at the time.

Errors and exceptions represent unusual or invalid processing.

If an exception is not caught and handled where it occurs, it is ______ to the calling method.

Each _______ clause on a try statement handles a particular kind of exception that may be thrown within the try block.

An object reference variable stores the ______ of an object.

A child class can _________ (redefine) the parent's definition of an inherited method.

Each object has a ____ and a set of ____.

Objects should be self-governing. Explain.

How are overloaded methods distinguished from each other?

Several references can refer to the same object. These references are ________ of each other.

A ______ reference can refer to different types of objects over time.

A parent's constructor can be invoked using the ______ reference.